—Have you thought about what to do next?— I know my business.A. What for?B. Why not?C. D

问题补充：

—Have you thought about what to do next?

— I know my business.

A. What for?

B. Why not?

C. Don’t worry.

D. No wonder.

答案：

A. What for?

B. Why not?

(答案→)C. Don’t worry.

D. No wonder.

解析：这是安慰对方的语言，“别为我担心，我知道该怎么做”。